The subject matter disclosed herein relates generally to agricultural implements and, in particular, to an air cart having multiple compartments from which different components of fertilizer may be distributed at separately controlled distribution rates to achieve a customized blend of fertilizer.
Air carts are commonly towed by tractors to apply seed, fertilizer, or micro-nutrients or any granular product to a field. The air cart includes a hopper having one or more compartments configured for holding product, generally seed or fertilizer. Air carts also generally include a volumetric metering system operable to measure a fixed volume of product per unit of linear distance from each tank and a pneumatic distribution system for delivering the product from the tank to the soil. A tilling implement may be towed in cooperation with the air cart to first open a row in the field, receive product from the air cart, and subsequently close the row over the distributed product. One or more compartments in the air cart may be filled with seed while one or more compartments may similarly be filled with fertilizer. The air cart controls distribution from each compartment such that one compartment provides seed and another compartment provides fertilizer at the desired rates.
Historically, fertilizer has been manufactured according to certain standard blends of nutrients. A standard blend may be defined in percentages, for example, as 20-10-10, meaning it contains 20 lbs. of nitrogen, 10 lbs. of phosphorous, and 10 lbs. of potassium per 100 lbs. of fertilizer. However, the standard blends may not be ideal for every type of crop or soil. Further, a farmer may want different blends of fertilizer for an initial application of fertilizer versus a subsequent application. Although custom blends of fertilizer may be ordered, customizing the fertilizer blend increases expense. In addition, separate custom blends may be required for each crop the farmer intends to plant. Thus, the farmer must maintain inventory of multiple blends at extra expense. Once delivered, the farmer is also limited in flexibility to select a different crop, for example, should weather conditions permit early planting or require later planting.